Polydorou E, Sakellis I, Soultati A, Kaltzoglou A, Papadopoulos TA, Briscoe J, Tsikritzis D, Fakis M, Palilis LC, Kennou S, et al. Avoiding ambient air and light induced degradation in high-efficiency polymer solar cells by the use of hydrogen-doped zinc oxide as electron extraction material. Nano Energy [Internet]. 2017;34:500-514.